1. Field of the Invention
The present invention relates generally to the field of digital optical compact disc information storage devices and, more particularly, the present invention relates to an improved compact disc storage device which incorporates at least one further storage element or area for storing additional information in a format which is both visually recognizable and machine readable. The information in a preferred embodiment is related to selective retrieval and/or identification of particular information contained in the compact disc. A corresponding disc player which is capable of reading both the information digitally stored in the compact disc as well as the information which is contained in the further storage element or area is also disclosed.
2. Description of the Related Art
Conventional digital optical compact discs are generally known in the art and provide a reliable and convenient mechanism for storing and retrieving information. In conventional optical discs, information is stored digitally, usually on a single side of the disc. A plurality of holes or pits in the surface of the disc define the stored information, and a laser beam is used to scan the surface of the disc to provide an output representative of the stored information. While these conventional systems generally provide satisfactory information storage and retrieval capability, these devices and the systems which access the stored information would be greatly improved by a system which is capable of repeatedly retrieving a selected portion of that information once the selected information has been initially identified or selected. The ability to maintain information related to the selection and/or retrieval of particular information contained in the disc, on the disc, would greatly enhance the performance of existing systems and increase overall consumer satisfaction with digital optical compact disc products.
The shortcomings of conventional compact disc storage and retrieval systems are apparent from the manner in which information is currently selected for playback in these systems. In conventional compact optical discs and in particular those optical discs which contain audio information such as music, the sound information is digitally stored in read-only format by the disc manufacturer. In optical compact discs which contain sound recordings, each individual selection is stored in a separate location called a track and each track is designated by a track number. The sound recording stored in the particular track is usually identified by its title and artist either by pre-printed material on the disc or in material which accompanies the disc. In these systems, the disc user can only read the information stored within the disc with a compact disc player and the user typically is not able to store additional information on the disc. When a user selects a particular compact disc containing the desired information or sound recording which the user would like to hear, the user must either listen to all of the selections on the disc or manually enter programming information into the compact disc player identifying the particular track or tracks which the user would like to hear.
Most conventional compact disc players are capable of playing selected recordings from digital optical compact discs. These disc players allow the user to program his or her track preferences into the machine so that the machine may skip undesired selections and play only those tracks or selections which the user wishes to hear. The track selection information is typically temporarily stored in a memory of the player while the disc player proceeds to play the selected tracks from the particular disc. In conventional compact disc player systems which are capable of playing selections from more than one disc at a time, the user is generally able to choose from the various selections on each of the discs which are inserted into the player by identifying the disc through its position in the player and then subsequently identifying the particular tracks which the user wishes to hear. (e.g., a user may select the desired tracks for play as follows: disc number 1, tracks 2, 7, 10; disc number 2 tracks 3, 5, 8, etc.) These conventional programmable disc players require relatively complex programming steps with which the user must become familiar with in order to select the particular tracks on the disc or discs which the user wishes to hear.
One of the problems with these conventional systems is that a person who desires to hear only particular selections from a given disc is required to use the disc player as an interface for making the selections, and the selection information is lost once the disc player has played the particular selection[s]or after the machine is turned off. As noted, the selection programming process for these systems can be fairly complicated especially in systems which are capable of playing a number of discs at a time. Additionally, this process must be repeated each time the user would like to listen to a particular disc after it has been removed from the machine because the selection information is not maintained with the disc.
It has been recognized, however, that in most instances, the particular track or track selections which the user initially identifies for playing from a particular compact disc are the same selections which the user will select at a later time so that the ability to maintain the selection information is therefore desirable. This is due to the fact that most digital optical compact discs, like most albums, have filler material which most listeners usually do not enjoy hearing or a person using a compact disc system may have certain favorite selections from a disc which they particularly enjoy.
One proposed solution to the problems identified above is disclosed in U.S. Pat. No. 4,872,151 invented by Smith. This reference describes a conventional digital optical compact disc having a magnetic storage element in the form of a magnetic strip for storing order of play data for the compact disc. The magnetic strip is attached to the disc and the order of play data stored in the magnetic strip can be maintained with the disc. Although the solution proposed by Smith addresses some of the problems identified in the art, the Smith disclosure has numerous disadvantages.
First of all, the apparatus disclosed in Smith requires that a person using the system interface with the compact disc player system in order to identify the selection information for a particular disc. As noted, this process can be fairly complex especially for systems in which a number of discs may be programmed at the same time for play. Additionally, because the selection information is stored magnetically on the disc, there is a significant risk that the selection information could be inadvertently lost due to accidental contact with the magnetic media or by exposing the magnetic media to a magnetic field. The system disclosed in Smith is also undesirable because the selection information is not readily ascertainable from viewing the surface of the disc. In order for a person using the system disclosed in Smith to determine which selections have been selected for play on a given disc, the person must insert the disc into the disc player so that a magnetic head in the disc player can read the magnetically stored track selection information. One further disadvantage is that the system disclosed in Smith requires fairly complex additions to existing disc player circuitry for implementation, most notably, the Smith design requires that magnetic read and write heads be incorporated into the disc player as well as fairly complex software for control of the magnetic heads in order to write information to the disc and read information from the disc.
Thus, there remains a need in the art for a compact disc and disc player system which is capable of maintaining compact disc selection information along with the disc in a non-volatile format which is at once machine readable, visually recognizable and manually inscribable without the use of a player.
Accordingly, it is an object of the present invention to provide a further information storage element or area on conventional digital optical compact discs which allows user selection information to be maintained in non-volatile format on the disc.
It is a further object of the present invention to provide a system for automatically reading and controlling a disc player via selection information stored on a digital optical compact disc.
It is another object of the present invention to provide a simple mechanism by which a person may manually select particular tracks on a compact disc for playing without the use of a compact disc player.
It is another object of the present invention to provide a storage mechanism for the track selection information which is both visually recognizable and machine readable.
It is a further object of the present invention to provide a design for reading disc selection information which is both simple to use and economical to implement.
It is a further object of the present invention to provide a further storage element or area on conventional digital optical compact discs which is compatible with existing optical discs and which may be easily applied to existing discs.
Other objects and advantages of the present invention will become apparent from the following summary of the invention, the drawings, and the detailed description of the presently preferred embodiments.